Tin perovskite transistors and complementary circuits based on A-site cation engineering

Abstract

Tin halide perovskites have the general chemical formula ASnX3, where A is a monovalent cation and X is a monovalent halide anion. These semiconducting materials can be used to fabricate p-type transistors at low cost and temperature and could be potentially integrated with n-type oxide-based transistors to create complementary circuits. However, the materials suffer from low crystallization controllability and high film defect density, resulting in uncompetitive device performance. Here we show that pure-tin perovskite thin-film transistors can be created using triple A cations of caesium–formamidinium–phenethylammonium. The approach leads to high-quality cascaded tin perovskite channel films with low-defect, phase-pure perovskite/dielectric interfaces. The optimized thin-film transistors exhibit hole mobilities of over 70 cm2 V−1 s−1 and on/off current ratios of over 108, which are comparable with commercial low-temperature polysilicon transistors. The transistors are fabricated using solution-processing methods at temperatures no higher than 100 °C. We also integrate the devices with n-type metal oxide transistors to create complementary inverters with voltage gains of 370, and NOR and NAND logic gates with rail-to-rail switching performance.